一种非典型声强向量阵-空间十字阵定向算法研究

A 0.2 m Spatial Cross-Shaped Array Based on Vector Sound Intensity Measurement for 2D DOA(Direction of Arrival) Estimation

提出了1种可在小尺度平台上安装的非典型声强向量阵-空间十字阵,它由空间正交形状的四基元组成,并且提出了一种纯相位定向算法,将该算法用于空间十字阵可以实现低频声源的全空间高精度定向。在理论上系统分析了阵形的有限差分误差、相位失配误差以及环境噪声引起的定向误差,并且用自制的声强阵支架在半消声室进行了定向实验,实验结果表明,信噪比为10 dB时,满足kd<1的条件下,空间十字阵对低频声源的俯仰角和方位角的定向误差都在1°之内。

Purpose. The typical vector sound intensity array for vector sound intensity measurement consists of 3 pairs of sensors; one of the sensors must be placed inside a platform. Such a typical vector sound intensity array, in our opinion, is still not convenient for engineering implementation. We present a non-typical four sensor array that is more convenient than the typical six-sensor array. The four sensors of this array form a spatial cross and its unique structure makes it adapted to being fixed in some small size platform. This array can find the DOA of a low frequency acoustic source with high precision by using a full-phase direction finding algorithm. We analyze theoretically and in detail the DOA estimation errors caused by finite difference approximation, instrumentation phase mismatch, and environmental noise. Experiments on two-dimensional DOA estimation with this array were conducted in a semi-anechoic chamber. In the experiments, the sound source incidences were （θ= 42°, φ= 3°） and （θ= 39°, φ= -15°）, where θ is the pitch angle and φ is the azimuth angle. The errors of DOA estimation of these two source points, given in Table 1, show that the spatial cross-shaped array with a small size of only 0. 2 m can achieve direction estimation precision of ±1° when SNR=10 dB and kd〈1, where k is wave number and d is the distance between the sensor pairs.